Part of this is that W3C standards are created separately from each other. But SVG 2 actually included a lot of work for harmonising SVG ways of doing things wi

Part of this is that W3C standards are created separately from each other. But SVG 2 actually included a lot of work for harmonising SVG ways of doing things with CSS ways of doing things (in those cases it was often CSS doing something differently that has existed in SVG before, though). There's pretty much not a single web technology that isn't plagued by such problems, as much of it came to be as some browser experimenting, others eventually following suit, and only then being standardised.